Furnace hot-water heater



Jan. 13, 1948. F. J. GORMAN 2,434,267

' FURNACE HOT WATER HEATER Filed Jan. l5, 1944 3 Sheets-Sheet l INVEN TOR.

ArroR/vfys Jan. 13, 1948. F J, GORMAN 2,434,267

FURNACE HOT WATER HEATER Filed Jan. l5, 1944 3 Sheets-Sheet 2 .9// Ff ,/83 A 87/ w/ /84 58? @[64 v '5" INVENTOR.

www/Mv Patented Jan. 13, 1948 UNITED STATES PATENT OFFICE 21 claims. l

My invention relates to improvements in a furnace hot water heater, and it consists of the combinations, constructions and arrangements hereinafter described and claimed.

This application is a continuation-in-part of my abandoned application on a furnace hot water heater, filed August 3, 1938, Serial Number 222,798.

An object of my invention is to provide a furnace hot water heater in which the same hot air furnace that is used for warming the rooms of the house is also used for heating water for a hot water tank. In this way, an installation of a hot air furnace and a separate hot water heating plant is avoided with a resulting saving in cost.

The type of furnace used is one which has a hot air duct leading to various rooms and a cold air return duct leading from the rooms back to the furnace. In this way, a closed circuit of heated air from the furnace to the rooms and from the rooms back to the furnace is maintained. I provide a separate hot air or heater duct communicating with the furnace hot air duct and with the cold air return duct. In the heater duct, I dispose a hot water heater and connect this with the 'not water tank. Dampers are provided in the two closed circuits and are automatically controlled by a room thermostat and by an aquastat for causing the hot air to flow to the rooms when the room thermostat calls for heat or to pass through the heater duct when the aquastat calls for heat. In winter time, hot air is caused to fiow through both the hot air duct and the heater duct. Very little extra heat is necessary for heating the water in the hot water tank because the heated air follows a closed circuit path from the furnace, through the heater duct and back to the furnace.

A modiiied form of the invention is also disclosedv wherein the casing has a partition dividing it into two chambers, one for the furnace and the other for the blower and the cold air return. I mount a by-pass damper in the partition and place the hot water heater in the furnace chamber and adjacent to the damper so that some of the furnace hot air will pass the water heater when the rooms are being heated and all of the hot air wi.l pass the water heater when the room dampers are closed and the by-pass damper is open. This does away with the need of a second casing for the water heater.

Other objects and advantages will appear in the following specification, and the novel features Z of the device will be particularly pointed out in the appended claims.

My invention is illustrated in the accompanying drawing forming a part of this application,

in which Figure 3 is a wiring diagram for the device shown in Figure 1;

Figure 4 is a schematic showing of a modied form of the device;

Figure 5 is a wiring diagram for the `device shown in Figure 4;

Figure 6 is a schematic showing of another modified form of the invention;

Figure 7 is a schematic showing of still another modified form of the invention; and

2o Figure 8 is an alternative wiring diagram for the devices shown in Figures 1, 4 and 6.

In carrying out my invention, I provide a hot air furnace indicated generaly at l and this furnace may be of any standard type desired. A

hot air duct 2 leads from the furnace to the various rooms and a cold air return duct 3 conveys the air from the rooms back to the furnace for reheating. A damper 4 is placed in the hot air duct and is actuated by a thermostatically operated control motor indicated generally at 5.

Any type of operative connection between the motor 5 and the damper 4 may be used and I have shown an arm B actuated by the thermostatically operated control motor 5 and connected to a damper arm l by means of a link 8. In

Figure 1, I show the damper 4 held in open position by the damper arm I.

A room thermostat 9 is electrically connected to the thermostatically operated control motor 5 in the customary manner and I have shown an electric conduit I0 extending from the thermostat 9 to the motor 5. The motor circuit is closed and opened by the room thermostat 9 in a manner hereinafter described. The room thermostat 9 may also be connected to an electrically controlled gas valve indicated diagrammatically at Il. An electric conduit l2 leads from the room thermostat 9 to the valve Il. The valve controls the flow of gas through a gas pipe I3 to a burner I4 and a pilot light l5 ignites the gas. It is obvious that an oil burner may be used in place of a gas burner as shown in my modified form, if desired, and that a forced draft through the furnace may be effected by a fan or blower 41.

3 The parts thus far described, are of standard construction and form no part of my invention except insofar as they cooperate with the parts now to be described. A hot air or heater duct I6 communicates with the hot air duct 2 at a point below the damper 4 and also communicates with the cold air duct 3 at a point adjacent to the furnace. A damper I1 is disposed in the inlet end of theA heater duct I6 and is operatively connected to the damper 4 so that the dampery I'I will be partially opened when the damper 4 is entirely opened and a closing of the damper 4, will entirely open the damper Il. Any type ofA connection between the two dampers for effectingi this operation will suice and in the drawing I have shown a link I8 connected to a damper-amm I9 which in turn is actuated byV the-damper 4l The link I8 operates a bell-cran-k lever 20 and the lever is connected by a link 2| to aidamper.A arm 22 that is connected-to the damper I1.

I dispose; a; hotl waterflheater 234 in,t the;` heater duct IB and this heater is shownonfaglarger scale inllieure, 2,-` The heaterA hasanrupper headerL 24 andr at lower l header,l 2`5- connected-fx togetherb bypipes 26. The heater is connected to a hotwaten tankA 21; seeA Figure 1', by,` meansV ofy a` Coldwater pipe 28 that leads to the header 25 and a return; hot water pipev 29, that-l leadshto'vtheheader- 2 4. The tank 2'I is provided with a coldqwater-A inlet pipe l3;! and ahot; water-outletpipe 3 I inthe-usual manner. Any type of heat transferring .means maybe placed in the ductL IG. The drawingshows a tube and fin type of hot watery-heater` although a.I honeycomb typemay be used...

I mount an aquastat 32 in thehotwater tank.l andthiscontrolsthegelectric.gas valve I-I through the medium of an electric conduit Sii-.that connects; theV aquastat;4 with; the= valve. Whenthe water temperature in1t'.he tankA ZIidrops belowa predetermined point, Ythe;aeuiastat willgcause the electric valve, II toopen ina manner presently` to be described i andthe pilot-f light I 5,-,willignite thegas issuing,fromtheburnen I4; 'Ifheheated air flowing, fromtthe furnacewill pass through the heaterduct I B; and will heat the .water-,in the` pipes 26. heatedmater-will ,bey displacedby.

the vcold water.- flowing from :the-tanklj through.

the, ppetandthe heated water williiow up,A war,d1ythr0ugh .the hot waterretumlnne .-ZlfleackI to thetank; This, perationwi11continueuntil, the water-has beenraised tothedesired temperature whereupon l, the aquastat, 3,2'- will; close` the. valve II. TheaquaStat-.mav control,theznwtor:l if desired.

It will be notedffromgure ,1,that-Lm0unt a heat-limit control 34 at theltopl of; thefurnace and when the temperature-inthe-furnacev passesv beyond a. predetcrimineelv point. thegcentrol .134; will reduce the ,flow of gas-to the., burner; by closing. thegas valve I I:` Arielectric conduit ;3 5 isshown extending from, the h eatflimit control 34 :.toythe. gas valve;

From they foregoing,v description or", thefvarious parts of thedevice, thegoperalonthereofmaybe readily understood;V

When the ,room` thermostat 9' closes,1itiwill closeA an electric circuitwhichwill causathe gas,valve. II to open and will'alsocause thegfthermostati-f ca11yoperated-control motor Beto-.Onenzthie damper 4.V Heated air will be; forced through'theffurnace by thelolower when thetemperaturefin the furnace.` reachesqapointtoecloseuthefblower controlls/Witch A48vvl1.eh in .tulnlconnectsithe.blower with. ag soureeg of 1 current.. This q. heatedf; air; will pass through the hot air duct Zito-theeVarious,

rooms, and a portion will be bypassed through the heater duct I6 because the damper I'I is partially open. The hot air owing through the duct I6 will warm the'water in the water heater 23 and this heated water will flow into the tank 2 in the manner already described. The heated air after being forced into the rooms will ow back to the furnace by means of the cold air return duct 3. The returning air willibe warmer thanthe atmospheric air and: thereforefless heat will' be necessaryto maintain the rooms at a proper temperature. When the rooms do attain this necessary temperature, the thermostat 9 will Acause the-moton' to close the damper 4, whereupon all of the heated air will ow through the heater duct: I 6. This will continue until the water n inthe tank2l. is-.raised to the desired temperaduct 3.

ture. The valve IIA will remain open until the demands of the room thermostat 9 or the aquastat 32 are met. When the rooms are at the desired temperatureand the water isf also =at; thedesired temperatureathelvalve I-I. will closefand-.shut off? the gasto the burner.

During warm weather., the damper -4. will:V remain closed and the damper I-I'I`` will ,be y held in wide-open position. Theburner I4 will be turned: onor oi by the valvev I Ifsolelyf.A according to thee demand of the aquastat 32, except that if fora any reason the'temperature within; the.; furnace should exceed the temperature-at which-.the-control 3,4; isset, this control will close the-.valve-I I.. Acorn parableA conditionwill obtain. during,v periods'l oft demand bye-the` room thermostat-91. Thaheated air will only,flowthroughftheheater ductV I6 andi, wil1=be returned tofthe furnace by thecoldair It is possible to mount a check damper- SB inthe return duct;3.to prevent any. possibility of the heatedair passing through` thisduct and: enteringv the house.- If desired the:k damper 36;- maybe operatively connectedto the-damper 4. tobe closed Whenfthe damperY 4 is.closed.

It will be seenthat-I providetwo closedcircuits, for. the heated air, one, tov-,theL rooms andback to.- the furnace; and the other to ithe .heat rtransfer ring means 23,and.back.to.the furnace.. The cost. of operatingrthe furnace is. reducedto aminimum dueto these two-closed `circuitfeaturea Should the return duct 3;be dispensedwith,.the1closed hot air circuits `would also,.be eliminated andv in this-case ,theduct. I couldcarry vthe ,heatedair directly, to., the. atmosphere... Such. an. arrange.-y mentwould notbe so .economical asthattcontem platedby thesclosed hotair Cireuta Itis DOS-- sibleA to have the return. duct3 eliminatedand stillhave the, duct Ik'communicate witlithe lower end` of thefurnace so` that.' theclosedlrelaton. of the water heatingduct' I6" to the furnace4 be retained.

It should be notedthat theroom thermostatin openingA the damper through the thermostatically operated'control'motor 5' actuatesl a contact in thecontrol'motor-that electrically cuts out`the, aquastat so long astheroom damper-4' is open. If this-were not the-case; the water uponP being heated to the desired extentI would causek the' aquastat` to shut offthe` burner v andV this would preventithe heat Yfromentering the rooms.- When' the` control motor closes-the damper- 4; the aquastat isagain-placedlin electrical connection with the burner valve.`

In the `wiring Y diagrannshown in Fig-urel 3', the` various .units are shown diagrammatically andraJ wire 3'I leads from a.source .ofs'currenti tothe furnace limit` control. switch ,34candlfrom there a wire ,3B-:leads .toga .relay 39'lwhich- `maygbe mounted in the damper motor housing if desired. A wire 49 connects with the relay and with the room thermostat 9. A return wire 4| extends from the room thermostat to the motor (not shown), enclosed within the damper motor housing 5. A wire 42 leads from the motor to the burner valve and a wire 45 extends from the burner valve back to the source of current.

When the room thermostat switch 9 is closed, the current will flow to actuate the damper motor 5 and to open the burner valve The current is controlled by the room thermostat 9 and the furnace limit control switch 34. The current energizes the relay 39 and opens a switch 44 which will break the circuit through the aquastat 32. When the room thermostat switch 9 is opened, the switch 44 will be closed because the relay 39 becomes de-energized and then when the aquastat switch 32 closes, a current will flow through the wire 3l, the furnace limit control switch 34, wire 38, wire 35, aquastat 32, wire 44a, switch 44, wire 46 to the wire 42, burner valve |l, wire 43, and back to the source of current. The water in the tank 27, when heated to the proper temperature, will open the aquastat switch 32. The furnace limit control switch 64 is a safety precaution to prevent the temperature in the furnace from rising to too high a degree. In Fig. 3, I have indicated the conduits I6, I2, 33 and 35 by dot dash lines. The blower 41 and switch 48 are on a separate circuit which connects with the source of current.

The invention is not to be restricted to a closed hot air system. The return cold air duct is to be regarded as a means for supplying cold air to the furnace, or generally, air having a temperature less than that of the air delivered by the furnace.

In the modified form of the invention shown in Figures 4 and 5 a portion of the cold air return conduit 50 (corresponding to the conduit 3) forms a part of the casing 5| that houses the hot air furnace 52. A partition 53 divides the casing 5| into two compartments 54 and 55. A blower 56 is placed in the compartment 55 and draws air from the cold air conduit 55 and forces it into the furnace compartment 54. From there the air is usually forced into the hot air conduit 57 that leads to the rooms or space to be heated. A damper 58 is designed to close the hot air conduit 51 and a damper 59 is designed to close the cold air return conduit 56. These two dampers have arms 58a and 59a that are operatively connected together by a link 69 so that both dampers will be opened and closed simultaneously. A damper control motor 5|, similar to the control motor 5, is connected to the damper arm 58a by a link 62. A room thermostat 63 is electrically connected to the damper control motor 6| in a manner hereinafter described and when the temperature in the room drops to a predetermined point, the room thermostat will close an electric circuit through the damper control motor for causing both dampers to swing into open position.

I show an oil burner 64 in Figure 4 and the closing of the room thermostat 63 will cause the oil furnace to function. Hot air will be given olf by the furnace 52 and this air will flow through the conduit 57 to the rooms and cold air will return by the conduit 50 back to the compartment 55 and thence to the furnace compartment 54, thus completing a closed hot air circuit. A blower control switch 65 is electrically connected to the blower 56 in a manner hereinafter described, so that when the temperature of the hot air issuing from the furnace reaches about 175 F.,

6 the blower 56 will be automatically started and will force'the heated air to the rooms and will draw the cold air from the rooms. In this way no cold air is blown into the rooms.

A limit control switch 66 is electrically connected to the burner 64 for opening the circuit to the burner and stopping it from functioning when the temperature of the furnace reaches 250 F. The switch 66 will close when the temperature drops below 175 F., and in this way the limit control switch protects the furnace.

The hot water tank 61 is similar to the hot water tank 21 and is connected to a hot water heater 68 (similar to the hot water heater 23) by pipes 69 and 70. The heater 68 is placed in the hot air compartment 54 at a point adjacent to an opening 1| in the partition 53. A by-pass damper 'I2 partially closes the opening 7| when the dampers 58 and 59 are fully open. The damper 12 is fully open when the dampers 58 and 59 are closed. A link 'I3 operatively connects an arm 12a of the damper 12 with an arm 58h of the damper 58 so that all three dampers will be actuated simultaneously by the damper control motor 6|. A hood '|4 may be placed over the heater 68 for directing the heated air from the compartment 54 into the compartment 50 when the dampers 58 and 59 are closed and the damper 12 opened.

An aquastat 15 is placed in the water tank 61 and is electrically connected by a circuit hereinafter described with the oil burner 64 for causing the latter to function when the aquastat switch closes even though the room thermostat 63 remains open.

The wiring circuit for the device shown in Figure 4 is shown in Figure 5. A wire 16 leads from a source of current and connects with the room thermostat 63. A wire 17 leads from the thermostat to the damper control motor 6|. A wire 18 leads from the motor to a relay 19 and from thencel to the limit control switch 66. A wire leads from the limit control switch 66 to a stack switch 8|. Figure 4 shows the stack switch placed in the smoke pipe 82 that leads from the furnace 52. Any type of switch 8| may be used and I have shown a bi-metal member 83 that will open the switch 8| when the heat in the pipe exceeds a predetermined point. A wire 84 leads from the switch 8| to the oil burner 64 and a wire 85 leads from the burner back to the source of current.

When the room thermostat 63 closes, current will flow through the various wires and units just mentioned and the burner 64 will be ignited. The damper control motor 6| will open the dampers 58 and 59 and swing the by-pass damper 'l2 to a point where it will remain only partially open. As soon as the temperature of the furnace reaches F., the switch 65 will close the circuit to the blower 56 through the wires 86, 81, and 88 and this will cause the blower to draw air in from the conduit 50 and to force air through the compartment 54 and into the conduit 57. A closed hot air circuit is now established between the furnace and rooms. As already stated, the blower is automatically turned on and off by the switch 65 which in turn is controlled by the temperature in the compartment 54.

It will be noted that during the time the room thermostat 63 is closed, the aquastat 75 will be disconnected from the burner 64 by the opening of a switch 89. The switch is opened by the energizing of the relay 19 and the relay will remain energized so long as the room thermostat 63 is 75 closed. Figure 4 shows that a portion of the hot airV issuing from `the compartment: 54 lwillpass into the hood14 and through the oneningl't which is partially closed bythe. damperll. The water heater 68 is heated to. Va certain-extent s0.. that the water temperature will be raisedin the wat-er tank 6,1.

When the room thermostat 6 3 opens,` therelay 19 will be de-.energized and the switch 89;.Wll close. Now if the aoluastat4 15, closes dueto the water in the tank 61 calling for heat. the wire. 90, connected to. the wire 86, will place the switch 15 in electrical connection with the wire- 16,;and a wire 9| leading from the aquastat. 15; to; the closed switch 89 will connect the aquastat with the wire 18, thus completing a circuit tothe o il burner 64. The opening of the switch 63 causes the dampers 58 and 59 to be closed bythe. damper control motor 6| and causes the by-pass damper 12 to be f ully opened. All of the` heat will now pass through the hood 14 and the openingl 1| and this will heat the water in the` water heater 68 so that the temperature of the water in the tank 61 will be quickly raised. The blower: 56 will be started automatically when the switch 6,5 is closed which means that. the heat in the compartment 54 has reached a temperature of'17'5" F. This second closed hot air circuit from the compartment 54 into the hood 14', past the water heater 68, through the opening 1|, into the compartment 55, and from the blower 56; back tothe compartment 54 will continue until the aquastat 15 is satisfied. The heat builds up rapidlybecause there is little heat loss. The limit control switch 66 stops the burner before-an excessive temperature is reached while the blower remains 4in operation so long as there is suilicient heat in the compartment 54. The burnerv starts again when the temperature drops to 175 F., by the closing of the switch 66, pro-vided that either the thermostat 63 or the aquastat 15 is demanding heat.

It is possible to dispense with the hood 14 and to cause a portion of the heated air owing through the conduit 51 to. heat the-water heater 68. I nd better results however, by using the hood and keeping the by-pass damper partially openwhen the dampers 58 and 59. are fullyopen.

In Figure 6 I show a slightly modedform of the device from that illustrated in Figure 4. In they modified form, the hood' 14; is dispensed with and the damper or` valve 12b is soconnected to the arm 58h. by the link 1.3 andthe arm 12a. as to be entirely closed vwhen the valve or damper 58 is fully open. The parts ofthe device shown in Figure 6 which are similarV to the parts shown in Figure 4 have been given corresponding reference numerals.

In the operation of this form ofthe invention an opening of the dampers or valves 58. and 5.9 and the entire closing of the damper or valve 12b will cause the heated air to flow from the `hot air furnace 52 up through Ythe conduit 5.1. to

the space to beA heated andl the cold air tobe returned by the conduit 50. A portionofvthe heated air flowing from the. furnace 52 and entering the conduit 51 will contact the water heater 68 and will heat the water therein so that this heated water will be conducted to. the water `tank 61. In this way thev furnace will heat both the space to be heated and the water in .the tank 0.1 when the room thermostat. 63Lis closed. Only -aportion of the heated airflowing into t-he .con- .duit 51 will contact with the water heater fdue sto the position the water heater occupiesfinthe `.cempartment, 54'.

.When the room. thermostat 63 is, satisfied, the, dempersy or valves 5.8, and 5,9.wi11 close and the damper. or valve 12b will-be fully opened. If now the water temperature `drops belowv a predetermined point` in the. tank 6 1,A the aquastat 15 will close an electric circuit to the burner 64 and cause the furnace 5.2; to deliver heated air into the compartment 54. This heated air will flow Past the water heater 68 and then pass through the. opening 1| into the compartment 5l. The blower 5,6 will function when the temperature of the heated air reaches a certain point and the closed hot air circuit: for the. hot water heaterI 68,'wi11 continue functioning until the aquastat15. is satisfied.

Still another modied form of the invention is shown in Figure 7. Here thev furnace |00 is placed in a casing compartment |0| whichv is similar to the compartment 54. Adamper |02 or valve is placed in a hot air conduit |03 leading from the. compartment. A return cold air conduit |04. conveys the air from the space to be heated back to a compartment 05. The compartment |05: is in the same casing that houses the com partment |0| and is separated therefrom by a partition |06. Ablower |01 is placed in the com partment, |05 and draws the air from the return duct |04.and delivers it through a passage |08 into, the lower portion of the compartment |0|. The returning air passes through air lters shown at |09. in the compartment |05. Y

A cold air damper ||0 is placed in the return conduit |04 and is operatively connected to the damper |02 so. that an opening of the damper |02 will cause the cold air damper ||0 to swing downwardly and open the. cold air return duct |04. The damper- |02 is pivoted at and has an arm ||2 that is connected by a link |3 to an arm ||4 which in turn, swings lthe cold air damper ||0 about its pivot ||5, A damper control motor ||6 similar to the motor 6|, has its arm ||1 connected to the arm ||2` by means of a link ||8. A room thermostat ||9 is in electrical connection with the motor ||6 so that when the temperature in the space to be heated drops below a predetermined point, the thermostat will close an electric circuit to cause the burner |20 to heat the air in the furnace |00. The thermostat will also cause the damper control motor I6 to swing the darnpers |02 and ||0 into positions for open;

ling the conduits |03 and |04.

I provide an opening I2! in the partition |08, this opening being closed by the cold air damper i|6 when the damper is swung into a positionfto open the return conduit |04. In this way the damper H0 performs two functions; inV one position itA closes the conduit |04 and uncovers the opening |2| whereas in the other position it closes the opening |21 and opens the conduit |04. I place a hot Water heater |22 in the compartment |05- and adjacent to the opening |2I. This hot water heater is connected by water pipes |23 and |24 to ay hot Water storage tank |25 so that a heating of the water in the hot water heater |22 willj heat the water in the tank |25. rIfhe tank |25, hasa cold water, inlet |26 and a hot Water outlet |21. An aquastat |28 is placed in the hot vwater tank |25 and will be electrically connected to the burner $2.0 when the water inthe tank |25 drops below a predetermined'temperature and when the room thermostat ||9 is satisfied.

The operation o fthis form ofv theA invention is scrriewha:4 similar tothe form. shown in Figure 6 in that. when the thermostat |:|9 closes, the

9 damper motor ||6 will cause the dampers |02 and to open the conduits |03 and |04. The closing of the thermostat also starts the burner |20 and hot air will flow from the furnace through the conduit |03 to the rooms or space to be heatedv and cold air will return through the conduit |04. The damper l I0 performs the function of the two dampers 53 and 12b in the form of the device shown in Figure 6 because when the damper ||0 opens the conduit |04, it will close the opening |2|. A portion of the hot air owing intothe conduit |03 will pass the hot Water heater |22 and cause the water in the heater to be raised in temperature.

When the room thermostat I9 is satisfied, the dampers |02 and ||0 will close the conduits |03 and |04. The damper ||0 in closing the conduit |04 will uncover the opening |2| and this will make a direct passage for the hot air from the compartment |0| into the compartment |05. If now the temperature of the water in the tank |25 drops below a predetermined point, the aquastat |28 will close an electric circuit to the burner |20 and the hot air from the furnace |00 will flow past the water heater |22 and through the opening i2! into the compartment |05. The blower |01 will aid this flow of air in the closed hot air circuit and the flow will continue until the aquastat |28 is satised.

The wiring diagram for both Figures 6 and '7 can be the same as that shown in Figure where a line voltage control circuit is shown throughout. Such wiring as is shown in Figure '1 follows the scheme disclosed in Figure 8. In Figure 8, I show a modern automatic control for the vdevice of Figure '1, in which the actual control circuits operate on twenty-four volts furnished by a small transformer provided in the main stack relay. The line voltage is used for the damper motor, the burner and the blower and connections are made by relays placed in the stack relay. Such controls are standard so I have indicated the wiring in Figure 8, somewhat diagrammatically. A brief description will sufce. The same wiring can be used with the other devices in Figures 1, 4 and 6.

The main voltage lines |28a and |29 connect with the damper motor H3. The stack relay shown at Sla is connected by wires |30 and |3| to the lines |28a and |29 and is connected to the burner by wires |32 and |33 carrying the line voltage. The blower motor |01 is connected to the wires |30 and |3| by wires |34 and |35, the wire |34 having the blower control 65 in series therewith.

'Ihe low voltage control circuit comprises the three wires |30 connecting the room thermostat H9 with the damper motor ||6. The thermostat H9 may be of the two contact type where the closing of the thermostat when the temperature drops below a predetermined point will cause the damper motor to make a one-half revolution to move the arm I1 through 180 to open the dampr-elay (not shown) When the dampers are closed by the damper motor, the auxiliary switch opens,

ers, and when the desired air temperature is 60 and have the aquastat |28 in series therewith.

Two shunt or short circuit wires |39 and |00 lead from opposite sides of the aquastat to a shunt switch (not shown) in the damper motor H6. When the thermostat ||9 is closed for heating cutting the aquastat back into the circuit. The auxiliary switch could take the place of the relay 19.

I claim:

l. The combination with a hot air furnace having a hot air duct leading therefrom to one or more rooms and a cold air return duct leading from the one or more rooms back to the furnace, a damper for the hot air duct, thermostatically controlled means responsive to the room temperature for opening and closing the damper, of a heater duct communicating with the hot air` duct between the damper and the furnace and also communicating with the return duct, a water heater placed in the heater duct, a hot water tank, pipe connections between the tank and heater for causing water heated in the heater to be transferred to the tank, a damper mounted in the heater duct and operatively connected to the first-named damper so that it will be partially opened when the first damper is fully opened and it will be fully opened when the first damper is closed, a burner for the furnace, a valve-controlled fuel supply for the burner, an aquastat for the hot water tank, separate means connecting the aquastat and thermostat to the fuel valve for controlling the ow of fuel to the burner, and means conditioned by the satisfaction of the thermostat for making the aquastatI connection effective when the aquastat is unsatisfied.

2. The combination with a hot air furnace having a burner, a fuel pipe for the burner, an electrically controlled valve for regulating the fuel passing to the burner, a hot air duct leading from the furnace, a cold air return duct communicating with the furnace, a heater duct communicating with the hot air duct and return duct, a damper for the hot air duct, a second damper for the heater duct, means connecting the two dampers together for maintaining the second damper partially open when the rst damper is fully opened and for fully opening the second damper when the rst damper is closed, a thermostatically controlled motor operatively connected to the firstl damper, a room thermostat for controlling the motor, a water heater placed in the heater conduit, a hot water tank connected to the heater for receiving hot water from the heater, an aquastat associated with the tank, a heat limit thermostat in thefurnace, separate means connecting the aquastat, room and furnace thermostats to the fuel valve for controlling the flow of fuel to the burner, and means conditioned by the satisfaction of the thermostat for making the aquastat connection effective when the aquastat is unsatisfied.

3. The combination with a closed hot air circuit for a house including a hot air furnace, a hot air Y conduit for conveying hot air from the furnace to the rooms and a cold air conduit for conveying cold air from the rooms back to the furnace, of a second closed hot air circuit including the furentete? municating with the hot water heater forereceiving hot; water therefrom,'a damper forsthe hot air lconduit, a second damper forthe heater conduit, and -means. interconnecting the dampers `for swinging the '.heater damper -towardpartially .closedposition .when the hot air'conduit damper is opened, Yand for swinging the 'heater damper towardppen p ositionas the hot air conduit damp- .er is swung toward closed position.

.4.;Ir1 a hotaiixheatng and domestic; het water supply system; `the combination with a 'hot-,air heating circuit including a heater, a rstrcasing ,sill-rounding vsaid,heater, a lspace to be lheated, supply and return ,conduits connecting said iirst casing ,to V.said space and providing ,for `the cir- `Qlllation of heated ,air from said ,casing to the space and back to the.easing; ,of a domestic'hot water heating circuit, .including a second casing, water heating .means within said .second teasing. `conduit means connecting saidsecondcasing to said supply and return conduits, 'motor controlled damper means vat thejjunction o fthe said supply ,conduit and said .cOnduitmea/n'thermo- '.Staticmeans responsiveto thetemperature o'fthe airiinsaid space regulating.saidmotorcontrolled damper means to provide f or the circulation :of

heatedv air tosaid space, `or to said., second .casing.

`The.,combination.with,a hot, airurnacelhaving iacoldair ,inlet-leadinggfrom the ,rooms Atothe furnace/. a hot air ductleadingirom thelfurnace ,to the rooms, a heater duct `communicating `with-the hot airduct and ,with the cold air inlet, alhot water heater placed ,in the heater Aduct, a hot water tank, connections between theheater and the tank for transferring heated Awater `from theiheater tothe tank, aiburnerfor the.f11rnace, athermostat for the roomsand an aquastatior the tank separate .means controllably connecting the thermostat and aquastat.to.theburner, means c onditioned'bythe satisfactionof the thermostat for making the `aquastat connection effective ,when the aquastat is unsatised, and means also 4controlled by the thermostat 4for .controlling the ihotair iiow into thehot air duct andthe heater ,duct f or raising the room .and water temperatures.

V6. Ifhecombination with a closed hot airccircuit VVfor a house .including ahot air furnace, Vmeans Vfor conveying Ahet ,air Vfrom the furnaceto A the rooms and .from the ,rooms `back to lthe furnace, a second closed hot air .circuit including the -furnaceas a partof the circuit, a'hot watergheater Aplaced'in the second circuit, a water tank con- 'nected with the heater for receiving hot water from the heater, aiburnerfor the furnace, a thermostat in the rooms and automatically lighting gthe burner when the room temperaturedrops bejlow a predetermined point, Yan aquastat f or ythe 4water 'tank and automatically lighting the same `iburner` when thewater temperature drops "below "a predetermined point if'the thermostat is satisfied, dampers 'for Acontrolling the liow of hot ;air -through lboth closed hot air circuits'and'a lthermostatically operated control motor Aconnected :nace,`a"burner"for the furnace, a first hot'fair ciri cuit havingsupply and return conduits connectv-i-ng the jfurnace-to the space tolbe heated, a secondihot air circuitcommunicating with the upper and'lower portions-of and including the furnace 'fas apart -of the-circuit, a water heating system `arranged-inheat exchange relation to the hot air A-inthe second circuit, separate valve means for respectivelycontrolling hot air iiow in the circuits, a Ithermostat Vresponsive to the temperagtureiof the-space andoperably connected to the `Yvalve V'means 'for controlling their positions, an

laquastat responsive to the temperature of the water in the water heating system, and means includingelectrical connections between the thermostatan'd burner=and the aquastat and burner -whereby rthe thermostat exercises primary con- '-trol on the `burner'and the aquastat controls the l"burner when the thermostat is open.

8. A hot 'air heating and domestic hot water supply system lcomprising a closed hot air heat- Tfing circuitincluding a heater, a casing surroundingsaidheater,aspace to be heated, supply and Areturn conduits connecting said casing 'to said espace' and rprovidinga hot air heating circuit for -thecirculation of heated air from said casing 4itolthe spaceand back to the casing; of adomestic `hot''water"heating circuit including said heater, water heating means disposed within said domesticihot water heating circuit and connected toa hot4 water tank; `thermostatically controlled fmeans sensitive :'to the air temperature in said ispaceffor turning onthe heater, said means in- ,.fcluding :a Vdamper for directing Vthe 'heated air 4into the rst hot air heating circuitwhen the air itemperature-in saidisrpace drops below a predeter- `minedlpoint and for causing the damper to close fthexrstlhot air heating circuit when-thethermo- =stat is satisiie'd; an aquastat sensitive to the 'rwater temperature in saiditank for turning on :the heater when the damper is closed; `a second -damperoperatively connected to the rst damper "and-being opened when the first damper is closed for directing the heated air into the domestic hot v-water heating circuit when thewater temperature drops below a predetermined point, `said second damper being held partially open Awhen -the first damper is fullyiopen for causing some 4heated air to iiow 4-into` the domestic hot water iheating circuit ywhen the Yheated air is flowing -through the closed hot air heating circuit.

-9. The combination -with a casing divided into ltwo compartmentslby a partition, a hot air furnace 4placedin one compartment, a conduitleading from the furnace compartment to the space to be^heated anda return conduit leading from 'the 'space-to the other compartment, a damper 'mounted in each conduit, thermostatically conltrolled means for Asimultaneously opening both dampers when theair temperature in said space ,dropsfbelow aipredetermined point, said partition ihaving a by-pass opening, a by-pass damper adapted'to yclose the opening and being operaktively connected to said rst-named dampers yso that a closing ofthe first-named dampers will 4ggpenthetry-pass damper and Yvice versa, a'water 'heaten placed adjacent to theby-pass opening. so thathot lairfiowinggthroughV the opening willheat the Water-in the heater, and a water tank conwith theroom thermostat for causing the damp- 70 nectedto'the waterheater-for receiving hot water ers-to directthe greater portion of hot air to 'the `rooms when-the room thermostat lights theburn- 7. lIn-a hotgair heating-and domestic hot water lfromlthe heater.

10. Ingcombination, a casing divided into two l compartments "by Ya jpartition, a furnace Aplaced `in OnecQmpartmenLand a blower in the other lsupply system, the combination'of-a rhot-'airefur- 75 "`for-forcingair`from the latter'compartmentinto the furnace compartment, a conduit leading from the furnace compartment to the space to be heated, and a second conduit leading from the space back to the blower compartment, a damper for the rst-named conduit, a thermostat in said space for opening the damper when the temperature in the space drops below a predetermined point, said partition having a by-pass opening for permitting heated air to flow from the furnace compartment into the blower compartment when the damper is closed, a by-pass damper operatively connected to the first-named damper and being opened when the rst damper is closed, a Water heater placed near the by-pass opening and in the furnace compartment, a hood for directing hot air from the furnace compartment past the heater and through the by-pass opening when the first damper is closed, a hot water storage tank communicating with the water heater an aquastat for the tank, a burner for the furnace, separate means connecting the aquastat and thermostat to the burner for controlling the flow of fuel to the burner, and means conditioned by the satisfaction of the thermostat for making the aquastat connection effective when the aquastat is unsatisfied.

11. In a hot air heating and domestic hot water supply system, the combination of a hot air furnace, a burner for the furnace, a rst hot air circuit having supply and return conduits connecting the furnace to the space to be heated, a second hot air circuit communicating with upper and lower portions of and including the furnace as a part of the circuit, a water heating system arranged in heat exchange relation to the hot air in the second circuit, separate valve means for respectively controlling hot air flow in the circuits, a thermostat responsive to the temperature of the space and including means operably connected to the Valve means for controlling their positions, an aquastat responsive to the temperature of the water in the water heating system, and means including electrical connections between the thermostat and burner and the aquastat and burner whereby the thermostat exercises primary control on the burner and the aquastat controls the burner when the thermostat is open, the separate valve means being connected for simultaneous movement and the first circuit valve means being closed when the second circuit valve l means is open,

12. In a hot air heating and domestic hot water supply system, the combination of a hot air furnace, a burner for the furnace, a first hot air circuit having supply and return conduits connecting the furnace to the space to be heated, a second hot air circuit communicating with upper and lower portions of and including the furnace as a part of the circuit, a water heating system arranged in heat exchange relation to the hot air in the second circuit, separate Valves in the supply and return conduits and in the second circuit for controlling hot air flow therethrough, a thermostat responsive to the temperature of the space and including means operably connected to all of the valves for controlling their positions, an aquastat responsive to the temperature of the water in the water heating system, and means including electrical connections between the thermostat and burner and the aquastat and burner whereby the thermostat exercises primary control on the burner and the aquastat controls the burner when the thermostat is open.

13. In a hot air heating and domestic hot Water supply system, the combination of a hot air furnace, a burner for the furnace, a first hot air circuit having supply and return conduits connecting the furnace to the space to be heated, a second hot air circuit communicating with upper and lower portions of and including the furnace as a part of the circuit, a water heating system arranged in heat exchange relation to the hot air in the second circuit, separate valves in the supply and return conduits and in the second circuit for controlling hot air flow therethrough, a thermostat responsive to the temperature of the space and including means operably connected to all of the valves for controlling their positions, an aquastat responsive to the temperature of the water in the water heating system, and means including electrical connections between the thermostat and burner and the aquastat and lburner whereby the thermostat exercises primary control on the burner and the aquastat controls the burner when the thermostat is open, the separate valves being connected for simultaneous movement and the first circuit valves being closed when the second circuit valve is open.

14. In a hot air heating and domestic hot Water supply system, the combination of a hot air furnace, a hot air supply conduit leading from the furnace to the space to be heated, a conduit for conveying cold air to the furnace, a local hot air circuit communicating with upper and lower portions of and including the furnace as a part of the circuit, separate valve means in the supply conduit and local circuit at the upper connection with the furnace, respectively, for controlling hot air flow therethrough, and Water heating means positioned anterior to the local circuit valve means and in constant heat' exchanging relation with the air in the furnace.

15. In a hot air heating and domestic hot water supply system, the combination of a hot air furnace, a hot air supply conduit leading from the furnace to the space to be heated, a conduit for conveying cold air to the furnace, a local hot air circuit comprising the furnace and cold air conduit as parts of the circuit and a connection between the upper portion of the furnace and the :cold air conduit, rst valve means for controlling hot air flow through the supply conduit, second valve means located in the connection for controlling hot air flow therethrough, and Water heating means positioned anterior to the second valve means and in constant heat exchanging relation with the air in the furnace.

16. In a hot air heating and domestic h-ot water supply system, the combination of a hot air furnace, a hot air supply conduit leading from the furnace to the space to be heated, a conduit for conveying cold air to the furnace, a local hot air circuit communicating with upper and lower portions of and including the furnace as a part of the circuit, separate valve means in the supply conduit and local circuit at the upper connection with the furnace, respectively, for controlling hot air oW therethrough, a thermostat in the space, means responsive to the thermostat for determining the positions of the valve means, and water heating means positioned anterior to the iocal circuitl valve means and in constant heat exchanging relation with the air in the furnace.

17. In a hot air heating and domestic hot water supply system, the combination of a hot air furnace, a hot air supply conduit leading from the furnace to the space to be heated, a conduit for conveying cold air to the furnace, a local hot air circuit communicating with upper and lower portions of and including the furnace as a part .cof the circuit,.rrst `valve'fmeans .inzthe supply conduit rand-second-valve means inthe flocal-cir cuit :at the upper connection with `the furnace .fior controlling hot-air flow, the valve means be- :ing connected rior -simultaneous movement, vand :water heating means gpositioned anterior =to the :second valve `means and :in constant heat 7exchanging lrelation ,with the fair in the furnace.

:18. -In :a hot air heating and ,domestic ,-hot -wagtersupply system, the combination of -a lhot :,airl furnace, a fhot air *supply conduit `.leading ffrom'the-furnaceto the `space to `be heated, a :conduit for conveying :cold .air to the-furnace, =alocalfhot=air circuit communicating with upper -and flower portions for and :including 4the furnace :as a ,part-cffthe-circuit, rstvalve means inthe supply conduit and-second Avalve means in the ,local :circuit at the upper connection with the Lfurnace for controlling lhot air flow, -the valve means --being connected for 'l simultaneous move- A ment, fa thermostat ,in the espace, means .responasive sto the thermostat rior :determining ithe positions of the valve means, `and water yheating ,means positioned ,anterior --to `the `second valve -means and iniconstantlheat exchanging relation iwiththe fair in fthe furnace.

19. :In ,a hot air rheating :and `domestic `water fsupplyssystem, V:the combination .of fa-hot l air furnace, a burner fforithe furnace, a 4conduit con- -necting-the -furnace'tothefspace ,to be heated, awo

:second ,conduitffor receiving'heated: air from the .,furnace, .-a -water ,heating system arranged in .heat -exchange relation to the hot air in the .secondiconduit separatevalve means for respectively controlling hot .fair -ilow in -the conduits, fa,

thermostat responsive tolthe temperature ofthe space and including zmeans -operably Aconnected to the -valve rmeans for-controlling their positions, .an aquastat-responsive ito the temperature-of the `water -in the =water :heating system, and means,l

- including electricalzconnections-between the ther- Amostatfand burner ,andthe taquastat and Aburner whereby-the thermostat exercises `primary conltrol Y.on the .burner and the :aquastat controls the V.burner -When the-thermostat is open.

,20, -In. a hot ,air Theating rand domestic .water supply system, Ithe combination of-a `hot air lfurnace, Va burner `for-the-furna, a iirst `hot air t circuit having-supply -and return, conduits con- ,necting 'the furnaceto the ,'space tolbe heated, .afsecond hotair circuitcommunicating Awith upper and lower portions of and ,includingthe furnace -as a :part-,of the circuit, ;a water heating system arranged-in heatl exchangefrelation -to the .hot .airin `the secondcircuit and also'arranged ,in heat-exchange relation topa portion of. the hot. rair vin lthe first hot .air .circuit, separate 4valve means l-for respectively controlling .hot .air flow ,-in the circuits, fa thermostat responsive to the ltemperatureof A,the `space and including means ,'operablyrconnected to the yvalve means for con- .trolling .their positions, Aan `aquastat responsive Y16 to 'the temperature -of the -water in the zwater heating system, and means including `electrical connections between the thermostatand `burner and the aquastat and burner whereby the thermostat exercises primary control on the burner Vand valve means for causing hot air to ow through the rst hot air circuit and shutting 01T any hot air flow through the second hot air circuit when the thermostat needs to be satisfied, the thermostat when satisfied causing the valve means to close the rst hot air circuitand open the second hot air circuit, land the aquastatcon- `trols the burner when the thermostat is open .for

causing hot air `to flow through .the `second .shot air circuit.

21. In a hot air heating and domestic hot lWater supply system, the combination of a hot 4air furnace, a burner for the furnace, a rst hot air circuit having supply and return conduits connecting the furnace to the space to be heated, a second hot air circuit communicating with the upper portion of the furnace and with the return conduit as apart of the circuit, a water heating system arranged in heat exchange relationto lthe hot air in the second circuit andalso arranged in heat exchange relation to a portion of the hot air in the first hot air circuit, separate valves in the supply and return conduits and connected together so that the conduits are either opened or closed simultaneously, the valve Vfor .the return conduit closing the second air circuit when opening the return conduit, a thermostat responsive to the temperature of the space and including means operably connected to ,both valves for controlling their positions, an aquastat responsive to the temperature of the water in the water heating system, and means including electrical connections between the thermostat and burner and the aquastat and burner whereby the thermostat exercises primary control on the burner for lighting the burner and causing the valves to open the conduits for the rst hotair circuit and close the second hot air circuit, the valves closing the conduits and opening the second hot air circuit when the thermostat is satised, and the aquastat when needed to be satis- `i-led controls the burner when the thermostat is open for causing hot air to flow through the second hot air circuit.

FRANK J. GORMAN.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 2,314,086 Giiords Mar. 16, 1943 2,331,907 Harrington Oct. 19, 1943 2,120,803 Grant June 14, 1938 1,843,566 Lake Feb. 2, 1932 2,163,910 Lattner June 27,1939 

